2 Functions
224
7SD5 Manual
C53000-G1176-C169-1
Figure 2-98
Characteristic settings of the zero-sequence voltage time dependent stage —
without additional times
Zero-Sequence
Power Stage
If you have configured the fourth stage as zero-sequence power stage (address
131
Earth Fault O/C
=
Sr inverse
), set the mode first: address
3140
Op. mode
3I0p
. This stage can be set to operate
Forward
(usually towards line) or
Reverse
(usually towards busbar) or
Non-Directional
(in both directions). If the stage is not
required, set its mode to
Inactive
. The zero-sequence power protection is to
operate always in line direction.
Address
3141
3I0p PICKUP
indicates the minimum current value above which this
stage is required to operate. The value must be exceeded by the minimum earth fault
current value.
The zero-sequence power S
r
is calculated according to the formula:
S
r
= 3
I
0
· 3U
0
· cos(
ϕ
–
ϕ
Comp
)
The angle
ϕ
Comp
is set as maximum-sensitivity angle at address
3168
PHI comp
. It
refers to the zero-sequence voltage in relation to the zero-sequence current. The
default setting 255
°
thus corresponds to a zero sequence impedance angle of 75
°
(255
°
– 180
°
). Refer also to margin heading „Zero Sequence Power Protection“.
The trip time depends on the zero sequence power according to the following formula:
Where S
r
is the compensated power according to above formula. S
ref
is the setting
value
S ref
(address
3156
) that indicates the pickup value of the stage at
ϕ
=
ϕ
comp
.
Factor
k
(address
3155
) can be set to displace the zero sequence time characteristic
in time direction, the reference value
S ref
can be set for displacement in power di-
rection.
The time setting
Add.T-DELAY
(address
3147
) allows an additional power-indepen-
dent delay time to be set.
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Содержание siprotec 7SD5
Страница 2: ...2 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 4: ...4 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 18: ...Contents 18 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 34: ...1 Introduction 34 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 444: ...2 Functions 444 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 580: ...4 Technical Data 580 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 682: ...Literature 682 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Страница 698: ...Index 698 7SD5 Manual C53000 G1176 C169 1 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...